Alloy



June 4, 1935. H WARNER 2,003,524

ALLOY Original Filed Aug. 27, 1931 Vacuum f6 f6 7210/( 'Il VIVI l vHill! Vacuum Pam/0 Patented June 4, 1935 NlTED STATES PATENT oFFlcEALLOY tion of Delaware Application August 27, 1931, Serial No. 559,696Renewed November 1, 1934 2 Claims.

This invention relates to light metal alloys having an aluminum ormagnesium base, and provides improvements therein.

Industry is greatly interested in light metal e alloys for structuralusanotably in connection with air-craft, motors, etc. For structural usethe light alloys duralumin andmagnalium are probably the mostsatisfactory at present used. There remains nevertheless a want for achanical or physical properties than possessed by those now on themarket, notably better tensile strength and greater resistance tofatigue; and better chemical properties, notably greater resistance tocorrosion.

The present invention provides improved light metal alloys havinggreater tensile strength, greater resistance to fatigue, and greaterresistance to corrosion compared with duralumin and magnalium, and whichare tough, ductile and machineable. Alloys of the present inventionfurther possess a good electrical conductivity.

Alloys according to the present invention have an aluminum or magnesiumbase and contain boron, vanadium, zinc, some magnesium when aluminum isthe base and some aluminum when magnesium is the base, the range thereofin the alloys being approximately in percent by weight as follows:

ao Aluminum base Percent Boron 0.25 to 1.5 Magnesium 0.5 to 1.5 Vanadium0.25 to 1. Zinc 1. to 4. 35 Aluminum 98. m92.

Magnesium base Percent Boron 0.25 to 1.5 Aluminum 0.5 to 1.5 49 Vanadium0.25to 1..

Zinc 1. to 4. Magnesium 98. to 92.

5 mina as indicated at II, sealed with a vacuumlight metal alloy oralloys possessing better metight cover I 2. Numeral I4 designates avacuumpump connected to the interior of the crucible preferably througha tank I5. Numeral i6 designates heating coils or windings around andbeneath crucible Hl connected to a supply I8 of elee- 5 tric current.Numeral 20 designates a mold in which the alloy may be cast. The mold2l) is contained in a closed chamber 22 which is connected to vacuumpump I4 through tank I5.

The metals of which the alloys are composed, 10 as set forth above,and.- within the ranges set forth above, are introduced into thecrucible I0, with the metal constituting the base surrounding the othermetals. The cover I2 is sealed onto the crucible, and a high vacuumproduced in the interiors of the crucible and chamber 22, an equilibriumof vacuum being maintained during heating in chamber 22 and crucible I0.Electric current in the coils I6 heats the crucible'and the metalscontained therein. Fusion is effected at a temperature of approximately700-800 Centigrade, this temperature being maintained for about 30minutes for a 1/,2 lpound charge.

After the fusion has been ycompleted as aforesaid and while a highvacuum is maintained in chamber 22, the melt is run into the mold 20whereupon the alloy is solidied or formed into an ingot or casting. bythe chill of the mold. For running the melt into mold 20 a siphon tube24, passing through the bottom of crucible I0 into the top of chamber 22above mold 20, may be provided.4 By manipulating cocks 21, 28 in thelines from the vacuum tank I5, to crucible I0 and chamber 22respectively, the pressure in crucible Ill may be raised (by admittingair thereto) while the vacuum is maintained in chamber 22, which resultsin the molten alloy in crucible I0 being siphoned through tube 24 intomold 20. For preventing freezing or solidication of the alloy in tube24, an electrical resistance heater 30 surrounding tube 24, may beprovided. The cast metal is allowed to stand'in the mold under vacuumuntil the temperature falls to a suitable or desired degree, whereuponair may be admitted and the cooling accelerated. After cooling, the castalloy is preferably aged by either immersing in hot oil or by othersuitable and well-known methods.

The alloys hereinbefore described are light, dense, tough, ductile,possess great tensile strength, are highly conductive electrically andPercent Boron .75 Vanadium .25 Magnesium 1. Zinc- 1. Aluminum 97 showthat it has a tensile strength of 35,000 to 40,000 pounds pei` squareinch, is tough, ductile, malleable and machineable, and after immersionin ve percent sulphuric acid for one week showed no visible attack whenexamined under a microscope, and has a specic gravity of about 2.8.

What is claimed is: 1. An alloy of aluminum, magnesium, boron, vanadiumand zinc (aluminum being the base) within the following ranges:

Percent Boron .25 to 1.5 Magnesium .5 to 1.5 Vanadium ,25 t0 1, Zinc 1.to 4. Aluminum 98. to 92.

2. An @lloy containing substantially threefourths percent boron,one-quarter percent vanadium, one percent magnesium, one percent zincand ninety-seven percent aluminum.

THOMAS H. WARNER.

